Indophenolsulfonic acids and process of making same.



monosul-fonic UNITED STATES ALBRECHT SCHMIDT AND GUSTAV KRONLEIN,

PATENT orFroE.

OF HOCHST-ON-THE-MAIN, GERMANY,

THE-MAIN, GERMANY, A CORPORATION OF GERMANY.

INDOPHENOISULFONIC ACIDS AND PROCESS OF MAKING- SAME.

No Drawing.

To all whom it may concern:

Be it known that we, ALBRECHT Sonnnn'r, Ph. D., chemist, and GUSTAV KRoNLEIN, Ph. D., chemist, citizens of the Empire of Germany,residing at Hiichst-on-the-Main, Germany, have invented certain new and useful Improvements in ,Indophenolsulfonic Acids and Processes of Making Same, of which the following is a specification.

As is known, the disulfonic acid of carbazol and its derivatives cannot be converted with p-nitrosophenol or p-aminophenol into indophenolsulfonic acids.

Now we'have found that by combining the acids of carbazols with phenol derivatives yielding indophenols,said derivatives comprising p nitrosophenols or their derivatives or p-aminophenols or their derivatives,-there can very readily be ob-' tained products which may be regarded as indophenolsulfonic acids and which, by the. usual reducing recesses, are converted into leuco compoun s. The monosulfonic acids of carbazol and its derivatives, used for this purpose as parent material can be produced by sulfonation in an indifferent solvent, for

fuming sulfuric acid, as described in a copending application of Schmidt, Kriinlein and Runne, Ser. N 0. 763,397, filed April 24, 1913. They form readily crystallizing salts. These indophenol sulfonic acids are blue bodies, in concentrated sulfuric acid with a blue color, in diluted alkalis and'in alcohol with a reddish-violet color. They have the general formula: I

wherein X stands for the, homologous series; H, methyl, ethyl, etc.; R for a cation, and Ar for an arylene residue. These new products and their lcuco compounds can be used as parent material for the manufacture of Specification of Letters Patent.

\ dissolved in concentrated sulfuric instance nitrobenzene, with sulfuric acid or very readily soluble in water, soluble uric acid. When the reaction is complete, the blue solution produced is poured onto a mixture of ice, common salt and sodium carbonate, and thus the dark-blue indophenolsulfonic acid, separated in the form of its sodium salt, is freed from the excess of the acid. It has the formula The free indophenolsulfonic acid and its salts dissolve very readily in'water and are Patented Feb. 16, 1915.. Application filed April 24, 1913. Serial No. 763,4;31.

decomposed by acids, with heat. The free acid dissolves in water to a blue solution, the salts giving a reddish-violet solution; when acid, the color becomesa pure blue. By reducing said indophenol with sodium sulfid. a Ieuco compound is obtained, which, by the addition of common salt, can be'isolated in the form of a gray precipitate. This leuco compound oxidizes quickly in the air and thus becomes again blue; it is readily soluble in water. The free leuco-indophenolsuL fonic acid is can be separated by an acid from the alkalisulfid solution.

Example II: 26.1 kilos of methylcarbazolmono-sulfonic acid, or the corresponding quantity of its sodium salt, are. dissolved in about ten times the quantity ofconcentrated sulfuric acid, then mixed, while cooling, with a solution of 12 kilos of nitrosophenol in 120 kilos of concentrated sulfuric acid and, after the reaction is finished, poured upon a mixture of ice, common salt and sodium carbonate. The separated indophenolsulfonic acid shows the same properties as those possessed by the indophenolsulfonic acid of carbazol described in Example I I If in the foregoing examples p-nitrosophenol is replaced by o-chloro-p-nitrosophenol and the methyl-carbuzol-monosulfonic acid by the corresponding ethyl compound, the corresponding chlor-substituted indophenol ethyl carbazol monosulfonic acidis obtained. For instance, 27.5 kilos of ethylcarbazol-monosulfonic acid, or the cor responding quantity of its sodium salt, are dissolved in about ten times the quan ty of concentrated sulfuric acid, and this solution is then mixed, while strongly cooling. with a solution of 15.8 kilos of o-chloro-pnitroso-phenol in 160 kilos of concentrated rather diliicultly soluble and I s'olves in concentrated sulfuric acid to a greenish-blue solution, the solution of the sodium salt in water being of a bluish-violet color. In a similar manner, said indophenolsulfonic acids may be produced by oxida-' tion withpaminophenol or its halogen compounds, instead of condensing with nitrosophonol, for instance in the following way:

Example III: 27 kilos of ethylcai'hazolmonosul'fonic acid, or the corresponding quantity of its sodium salt, are dissolved in about ten times the quantity of concentrated sulfuric acid, ,then mixed with a solution of 10.7 kilos of p-aminophenol in 107 kilos of concentrated sulfuric acid: to this mixture are added, while strongly cooling, 21 ki os of powdered manganese dioxid (conts ling 85 per cent. of Hull), and the mass poured onto a mixture of ice and common salt. The separated indophenolsulfonic acid possesses the same properties as that de scribed in Example II. If the p aniinophenol is replaced by Qfldichloro-4-aminophenol. the corresponding dichlorindophenolcarbazol-sulfonic acid is obtained, the process for preparing the latter being as follows:

Example IV: 27.5 kilos of ethylcarbazolmonosultonic acid, or the corresponding quantity of its sodium salt, are dissolved in about ten times the quantity of concentrated sulfuric acid. then mixed with a solution of 17.8 kilos of 52.6-dichloro-l-aminophenol in 180 kilos of concentrated sulfuric acid; to this mixture are added, While strongly cooling. 21 kilos of manganese dioxid (containing 85 per cent. of MnU and the mass is poured ontoa mixture of ice and common salt, whereupon the indophenol sull'onic acid produced separates. It dissolves in concentrated sulfuric acid with a greenish-blue color, the solution of the so dium salt in water being of a bluish-violet color. 4 7

Having no describe-.1 our invention, what We claim, is:

1. The process of manufacturing indophenolsulfonic acids of the carloazols, which consists in causing the inonosulfonic .acids of the carhazols to react with phenol derivatives yielding indophenols, substantially as described.

2. As new products, the indophenolsulfonic acids obtainable from the monosulfonic acids of a carbazol and a phenol derivative yielding lndophenol, having the formula:

c ii mx so nyn'zAr-io" wherein X for the series: H, methyl, ethyl, all; it for arylene remdue; lacing blue bodies, soluble in Water and in concentrated sulfuric acid CHI-I6 (NH) son .uze n o being a blue body. so hie in water and in concentrated sulfuric with a blue color, in diluted alkalis and in alcohol with a reddish-violet color.

In testimony whereof, we atiix our signatures in presence of two Witnesses.

ALBRECHT SCHMIDT. GUSTAV KRGNLEIN.

Lea

\Vitnesses JEAN Gianni) CARL Geese.

cation, and Ar for an 

